Compounds comprising a hibonite structure and a method for their use

ABSTRACT

Novel colored compounds with a hibonite structure and a method for making the same are disclosed. The compounds may have a formula AAl 12−x−y M a   x M b   y O 19  where A is typically an alkali metal, an alkaline earth metal, a rare earth metal, Pb, Bi or any combination thereof, and M a  is Ni, Fe, Cu, Cr, V, Mn, or Co or any combination thereof, and M b  is Ti, Sn, Ge, Si, Zr, Hf, Ga, In, Zn, Mg, Nb, Ta, Sb, Mo, W or Te or any combination thereof. Compounds with varying colors, such as blue, can be made by varying A, M a  and M b  and their relative amounts. Compositions comprising the compounds and methods for making and using the same are also disclosed.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of International Application No. PCT/U.S.2015/017983, filed on Feb. 27, 2015, which claims the benefit of U.S. Provisional Patent Application No. 61/946,383, filed on Feb. 28, 2014, which prior applications are incorporated herein by reference in their entirety.

ACKNOWLEDGMENT OF GOVERNMENT SUPPORT

This invention was made with government support under DMR0804167 awarded by the National Science Foundation. The government has certain rights in the invention.

FIELD

This invention concerns hibonite compounds, particularly colored hibonite compounds, compositions comprising the same, and a method for making and using the compounds and compositions.

BACKGROUND

Blue inorganic pigments, such as cobalt blue (CoAl₂O₄), ultramarine (Na₇Al₆Si₆O₂₄S₃), Prussian blue (Fe₄[Fe(CN)₆]3), and azurite (Cu₃(CO₃)₂(OH)₂), are known. However, these known compounds all suffer from environmental and/or durability issues. For example, prussian blue liberates HCN under mild acidic conditions, and ultramarine and azurite are not stable with respect to heat and acidic conditions. Additionally, commercial processes for making ultramarine produce significant SO₂ emissions.

SUMMARY

In view of the above, there is a need for new, stable inorganic pigments comprising substantially environmentally benign and earth abundant components. Disclosed embodiments of the present application address this need and provide novel, colored compounds and a method for making and using such compounds. Certain disclosed compounds are synthesized blue hibonite compounds. In some embodiments the compounds have a formula I AM₁₂O₁₉  I. With reference to formula I, A is selected from an alkali metal, alkaline earth metal, rare earth metal, Pb, Bi, or any combination thereof, and M is selected from Al, Fe, Ni, Ti, V, Cr, Mn, Co, Cu, Zn Ga, Ge, Si, In, Sn, Mg, Zr, Hf, Nb, Ta, Sb, Te, Mo, W, or any combination thereof. As used herein, the term metal also includes metalloids.

Also disclosed herein are compounds having a general formula II AAl_(12−x−y)M^(a) _(x)M^(b) _(y)O₁₉  II. With reference to formula II, A is selected from Ca, Sr, Ba, Mg, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof, M^(a) is selected from Ni, Fe, Cu, Cr, V, Mn, or Co or any combination thereof, and M^(b) is selected from Ti, Sn, Ge, Si, Zr, Hf, Ga, In, Zn, Mg, Nb, Ta, Sb, Mo, W or Te or any combination thereof. In some embodiments, x is from 0.01 to less than 12, y is from 0 to less than 12, x+y is less than 12, and if y is 0 then x is from 0.01 to less than 1. In other embodiments, x is from 0.01 to less than 1, y is from 0 to less than 12, and x+y is less than 12. In certain embodiments, x is from 0.01 to less than 12, y is from 0.01 to less than 12, and x+y is less than 12.

In some examples, M^(a) comprises Fe and y is greater than 0, such as greater than or equal to 0.01 or greater than or equal to 0.1. Alternatively, M^(a) may comprise Fe and at least one additional metal selected from Ni, Cu, Cr, V, Mn, or Co. In other examples, M^(a) is selected from Ni, Cu, Cr, V, Mn, or Co or any combination thereof.

M^(a) may comprise at least two metals selected from Ni, Cr, Cu, V, Mn, Co or Fe, such as V and at least one additional metal selected from Ni, Cr, Cu, Mn, Co or Fe, or Cr and at least one additional metal selected from Ni, V, Cu, Mn, Co or Fe.

In some embodiments of formula II, A is A¹ _(1−z)A² _(z), where A¹ is selected from Ca, Sr, Ba, Mg, Sc, Y, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof, A² is selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or any combination thereof, and z is from 0 to less than 1.

In any of the above embodiments, if M^(a) is Mn and M^(b) is Mg then x+y may be less than 1, such as less than or equal to 0.95 or less than or equal to 0.9, or x+y may be greater than 1, such as greater than or equal to 1.05 or greater than or equal to 1.1.

In some embodiments M^(a) comprises Ni, Co or any combination thereof, and in other embodiments, M^(b) comprises Ti. In particular embodiments A is Ca, La, Sr or any combination thereof. In some examples, x is from 0.01 to 2 and/or y is from 0 to 2 or from 0.01 to 2, and in certain examples, x+y is less than or equal to 4. Compounds having formula II may also have a hibonite crystal structure.

In some particular embodiments of formula II, M^(a) is Co or Ni. In some particular examples, M^(b) is selected from Ti, Ge, Sn or any combination thereof, and/or x is from 0.05 to 1.5.

In some embodiments, the compounds are chromophoric, i.e. they absorb certain wavelengths of visible light and transmit or reflect other wavelengths, and in certain embodiments they have a blue color. The blue color may have a wavelength of from about 440 nm to about 510 nm, typically from about 450 nm to about 475 nm. In any of the above embodiments, the compound may be a synthesized blue hibonite compound.

Also disclosed are embodiments of a composition comprising a disclosed compound and at least one additional component. The composition may be, for example, a paint, an ink, a dye, a glass, a plastic, an emulsion, a fabric, or a cosmetic preparation. Examples of additional composition components include, without limitation, a binder, a solvent, a catalyst, a thickener, a stabilizer, an emulsifier, a texturizer, an adhesion promoter, a UV stabilizer, a flattener, a preservative, a polymer, a dispersion aid, a plasticizer, a flame retardant, an oxide of a metal, or any combination thereof. In some embodiments where the composition is a glass, the additional component is an oxide of a metal, including, but not limited to, oxides of silicon, boron, germanium or any combination thereof. In some embodiments, the composition has a blue color, and in certain embodiments the blue color has a wavelength of from about 440 nm to about 510 nm, preferably from about 450 nm to about 475 nm. Optionally, the composition may comprise at least one additional compound disclosed herein, and this additional compound may have formula I.

Also disclosed are embodiments of a method for making disclosed compounds and compositions. One disclosed embodiment comprises selecting the metals desired in the compound, providing reactants comprising the desired metals, and combining the reactants in stoichiometric amounts to achieve a desired final ratio of the metals in the compound. The combination of reactants is then heated at an effective temperature and for an effective period of time to make the desired compound. In certain embodiments, the effective temperature is from about 1,200° C. to about 1,500° C., and the time is from greater than zero hours to about 48hours.

In certain embodiments, the reactants comprise metal carbonates, metal oxides, metal nitrates, metal hydroxides or combinations thereof. In some embodiments the reactants are provided in a powdered form, and optionally may be pressed into a pellet before heating. The method may further comprise grinding the pellet after heating to produce a powder, pressing the powder into a pellet, and heating the pellet at a temperature of from about 1,300° C. to about 1,500° C. for from greater than zero hours to about 48 hours.

Embodiments of a method for making disclosed compositions comprise providing the compound and combining it with at least one additional component to make the composition.

Also disclosed are embodiments of a method of varying the color in a compound with formula II. In certain embodiments, the method comprises selecting metals A, M^(a) and M^(b) and the values of x and y to provide a desired color. Reactants are then selected comprising the desired metals, and are combined in stoichiometric amounts according to the values of x and y. The combination of reactants is heated at an effective temperature for an effective period of time to make the desired compound with the desired color.

Additionally, disclosed are embodiments of a method of using a disclosed compound, comprising providing a composition comprising the compound and applying the composition to a surface.

The foregoing and other objects, features, and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 provides a representation of the crystal structure of hexagonal CaAl₁₂O₁₉ with a hibonite structure, with Ca atoms in dark gray; oxygen atoms in red; AlO₆ octahedra in cyan, yellow and pink; AlO₅ trigonal bipyramids in dark blue; and AlO₄ tetrahedra in green.

FIG. 2 provides a comparison of XRD patterns and pellet colors illustrating the difference between the pure nickel-doped hibonite phase (CaAl₁₀TiNiO₁₉ as an example) disclosed herein and the nickel-containing CaAl₁₂O₁₉ mixed phase made according to the method disclosed by Costa et al.

FIG. 3 provides a series of color photographs of blue pellets and powders of CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0-1.2) demonstrating that color can be selected by the appropriate selection of metals and their relative amounts.

FIG. 4 provides a series of color photographs illustrating various colors of exemplary compounds with hibonite structure, having the formulae CaAl_(12−x−y)M_(x)Ni_(y)O₁₉ (M=Ti, Sn, Ge, Sb, Nb; x,y=0.2-0.5).

FIG. 5 provides a series of X-ray powder diffraction patterns for CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0-1.2) solid solutions.

FIG. 6 provides the results of cell edge calculations by whole pattern fitting for CaAl11Sn_(0.5)Ni_(0.5)O₁₉.

FIG. 7 provides unit cell dimensions in angstroms (Å) for cell edges ‘a’ and ‘c’ for solid solutions of CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0-1.2), illustrating that as the composition changes, the dimensions of the crystal vary correspondingly.

FIG. 8 provides unit cell volumes in cubic angstroms (Å³) for solid solutions of CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0-1.2), illustrating that the unit cell volume varies correspondingly with the changes to the composition.

FIG. 9 provides a series of diffuse reflectance spectra for CaAl_(12−2x)Ti_(x)Ni_(x)O19 (x=0-1.2) solid solutions, indicating that as x increases absorbance of light with wavelengths in the blue region of the spectrum remains low, but absorbance in other regions of the spectrum increases, resulting in blue colored compounds.

DETAILED DESCRIPTION

I. Compounds

A. Overview

The mineral known as hibonite has the ideal formula CaAl₁₂O₁₉. It rarely occurs naturally on Earth but has been observed frequently in meteors. As with most minerals, small amounts of other elements are found in hibonite samples. The other elements that have been reported in hibonite mineral samples are Ti, V, Cr, Mg, Si, La, Ce, Y, Sc and Th. The amounts of these trace elements are usually less than 1% and always less than 4%. It is notable that none of the many mineral samples analyzed contained detectable amounts of Ni, Cu, Zn, Ga, or In. The detection limit of these analyses is such that any amount exceeding about 0.01% would be found. Thus the compounds disclosed herein are very different than any observed in mineral samples of hibonite.

Although the color of pure CaAl₁₂O₁₉ hibonite is white, mineral samples are normally colored due to trace elements or defects. Observed colors are grey, dark brown, orange and blue. Attempts to correlate color with trace elements or defects have not led to a consensus.

The color of crystals is often very different from that of the powder obtained by grinding the crystals. For example, crystals of CoAl₂O₄ are black, but powder of the same composition and structure is a bright blue. Bright blue sapphire crystals yield a pale blue powder when ground up. Thus, it might be expected that grinding up blue hibonite crystals would produce a pale blue powder that would be of little commercial interest as a pigment.

Pure CaAl₁₂O₁₉ is white with a structure generally described in space group P6₃/mmc with unit cell dimensions of a=b=5.5587 Å, c=21.8929 Å, α=β=90°, γ=120°. This hexagonal crystal structure can be viewed as two-dimensional sections perpendicular to the c axis with alternating “spinel blocks” and trigonal bipyramidal blocks (FIG. 1). Without being bound by any particular theory, it currently is believed that there are five different coordination sites for Al, including three distinct octahedra, one tetrahedron, and an unusual trigonal bipyramid connected as a corner-sharing, edge-sharing or face-sharing polyhedral network. The cation in the trigonal bipyramid polyhedron is usually displaced from the center.

The Subramanian group at Oregon State University recently discovered that a surprisingly intense bright-blue color can be obtained when Mn³⁺ is introduced into the trigonal bipyramidal sites of hexagonal YInP₃. A range of blue colors can be obtained over much of the YIn_(1−x)Mn_(x)O₃ solid-solution by substituting Mn for In. Similar blue color is obtained when Mn3+is introduced into trigonal bipyramidal sites in other layered oxides. The resulting blue color is a consequence of both the crystal field splitting associated with the trigonal bipyramidal coordination and the short apical Mn—O bonds.

Costa et al. reported so-called Ni-doped hibonite as a new turquoise blue ceramic pigment, the color of which, however, is in fact only turquoise (G. Costa, et al. Journal of the European Ceramic Society 29 (2009) 2671-2678). Costa et al. provide no structural analysis, and the X-ray diffraction patterns displayed SnO₂ as the major phase with very small amount of hibonite in the mixture. FIG. 2 provides a comparison of the XRD patterns and pellet colors of the pure nickel-doped hibonite phase of CaAl₁₀TiNiO₁₉, as disclosed herein, and the nickel-containing CaAl₁₂O₁₉ mixed phase made according to the procedure disclosed by Costa et al. The top line of FIG. 2 shows an XRD pattern illustrating single phase CaAl₁₀TiNiO₁₉ hibonite as described herein, with a deep sky blue pellet color. The middle lines in FIG. 2 provide calculated XRD patterns for hibonite CaAl₁₂O₁₉ and cassiterite SnO₂. And the bottom line in FIG. 2 provides the XRD pattern taken from the paper by Costa et al. indicating a mixed phase with a light turquoise color: A—anorthite; C—cassiterite; H—hibonite.

Given the very small amount of hibonite detected, and the fact that SnO₂ is grayish white and NiAl₂O₄ is dark turquoise, the color of the Costa et al. material is most likely not from a hibonite phase.

B. Compounds

Disclosed herein are compounds, typically having a hibonite structure, and in certain embodiments the disclosed compounds are colored compounds. In some embodiments, the compounds have a space group P6₃/mmc.

The disclosed hibonite compounds typically have a general formula I AM₁₂O₁₉  I where A is selected from an alkali metal, an alkaline earth metal, a rare earth metal, Pb, Bi or any combination thereof; and M is selected from Al, Ni, Ti, V, Cr, Mn, Fe, Co, Cu, Zn Ga, Ge, Si, In, Sn, Mg, Zr, Hf, Nb, Ta, Sb, Te, Mo, W or combinations thereof. In other embodiments, A is selected from Ca, Sr, Ba, Mg, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof. In some embodiments, M comprises Al, one or more metals selected from Ni, Cr, Cu, V, Mn, Fe, or Co, and optionally one or more metals selected from Ti, Sn, Ge, Si, Zr, Hf, Ga, In, Zn, Mg, Nb, Ta, Sb, Mo, W or Te.

Also disclosed herein are compounds having a general formula II AAl_(12−x−y)M^(a) _(x)M^(b) _(y)O₁₉  II. With reference to formula II, A is selected from an alkali metal, alkaline earth metal, rare earth metal, Pb, Bi or any combination thereof; M^(a) is selected from Ni, Fe, Cu, Cr, V, Mn, or Co or any combination thereof; M^(b) is selected from Ti, Sn, Ge, Si, Zr, Hf, Ga, In, Zn, Mg, Nb, Ta, Sb, Mo, W or Te or any combination thereof. Typically, A is selected from Ca, Sr, Ba, Mg, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof. In some embodiments, x is from 0.01 to less than 12, y is from 0 to less than 12, x+y is less than 12, and if y is 0 then x is from 0.01 to less than 1. In other embodiments, x is from 0.01 to less than 1, y is from 0 to less than 12, and x+y is less than 12. In certain embodiments, x is from 0.01 to less than 12, y is from 0.01 to less than 12, and x+y is less than 12.

In some examples, A is A¹ _(1−z)A² _(z), and A¹ is selected from Ca, Sr, Ba, Mg, Sc, Y, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof; A² is selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or any combination thereof; and z is from 0 to less than 1, such as from 0 to 0.98, 0 to 0.95, or 0 to 0.9.

In some embodiments, M^(a) comprises Fe and y is greater than 0, such as greater than or equal to 0.01 or greater than or equal to 0.1, and in some other embodiments, M^(a) comprises Fe and at least one additional metal selected from Ni, Cu, Cr, V, Mn, or Co. In other embodiments, M^(a) is selected from Ni, Cu, Cr, V, Mn, or Co or any combination thereof.

In any of the above embodiments, if M^(a) is Mn and M^(b) is Mg, then x+y may be less than 1, such as less than or equal to 0.95 or less than or equal to 0.9, or x+y may be greater than 1,such as greater than or equal to 1.05 or greater than or equal to 1.1.

In some embodiments, y is from greater than 0 to less than 12, such as from 0.01 to less than 12, or from 0.1 to less than 12. In other embodiments, M^(a) comprises at least two metals selected from Ni, Cr, Cu, V, Mn, Co, Fe. In some examples, M^(a) comprises V and at least one additional metal selected from Ni, Cu, Cr, Fe, Mn, or Co. In other examples, M^(a) comprises Cr and at least one additional metal selected from Ni, Cu, Fe, V, Mn, or Co.

In some examples, x+y is less or equal to 4, and in other examples, x is from about 0.01to about 2, and/or y is from 0 to about 2 or y is from about 0.01 to about 2.

While not being bound to any particular theory, is it believed that M^(a) cations are chromophores, i.e. they are the part of the compound that is responsible for the color, and that M^(b) cations can be used to enhance the color and/or for charge balance.

In certain embodiments, M^(a) comprises Ni, La, Co or any combination thereof. In some particular embodiments of formula II, M^(a) is Co or Ni. In some embodiments, x is from 0.05 to 1.5 and/or M^(b) is selected from Ti, Ge, Sn or any combination thereof.

In some working embodiments, exemplary compounds were prepared where M^(a) comprised Ni or Co. Other compounds were prepared such that M^(b) comprised Ti. In certain working embodiments, A comprised Ca, Sr, La, Ce, Pr, Nd, Y, Sc, K, Na, Rb, Mg, Ba, Yb or combinations thereof. In some working embodiments, A was Ca and Sr, Sr and La, Ca and La, Ca and Y, Ca and Ce, Ca and Pr, Ca and Na, Ca and K, Ca and Rb, Ca and Cs, Ca and Mg, Ca and Ba, Sr and Y, Sr and Ce, Sr and Nd, Sr and Pr, Ca and Sc, Ca and Yb, or Ca and Nd. In other working embodiments, A was Ca, Sr, Ce, La, Pr or Nd, and in particular working embodiments A comprised Ca, La, Sr or any combination thereof.

Exemplary compounds according to the present invention are selected from CaAl_(11.8)Ni_(0.2)O₁₉, CaAl_(11.5)Ni_(0.5)O₁₉, CaAl₁₁Sn_(0.5)Ni_(0.5)O₁₉, CaAl₁₀SnNiO₁₉, CaAl₁₁Zn_(0.5)Ni_(0.5)O₁₉, CaAl₁₁Ge_(0.5)Ni_(0.5)O₁₉, CaAl₁₀GeNiO₁₉, CaAl₁₁Ga_(0.5)Ni_(0.5)O₁₉, CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, CaAl₁₀Ti_(0.5)Si_(0.5)NiO₁₉, CaAl₁₀Ti_(0.5)Ge_(0.5)NiO₁₉, CaAl₁₀Ti_(0.5)Sn_(0.5)NiO₁₉, CaAl₈TiSnNi₂O₁₉, CaAl₁₀TiNi_(0.5)Cu_(0.5)O₁₉, CaAl₁₀TiNi_(0.5)Cr_(0.5)O₁₉, CaAl₁₀TiNi_(0.5)Zn_(0.5)O₁₉, CaAl_(11.8)Ti_(0.1)Ni_(0.1)O₁₉, CaAl_(11.6)Ti_(0.2)Ni_(0.2)O₁₉, CaAl_(11.4)Ti_(0.3)Ni_(0.3)O₁₉, CaAl_(11.2)Ti_(0.4)Ni_(0.4)O₁₉, CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, CaAl_(10.8)Ti_(0.6)Ni_(0.6)O₁₉, CaAl_(10.6)Ti_(0.7)Ni_(0.7)O₁₉, CaAl_(10.4)Ti_(0.8)Ni_(0.8)O₁₉, CaAl_(10.2)Ti_(0.9)Ni_(0.9)O₁₉, CaAl₁₀TiNiO₁₉, CaAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉, CaAl₈Ti₂Ni₂O₁₉, Ca_(0.8)Sr_(0.2)Al_(11.6)Ti_(0.2)Ni_(0.2)O₁₉, Ca_(0.6)Sr_(0.4)Al_(11.2)Ti_(0.4)Ni_(0.4)O₁₉, Ca_(0.4)Sr_(0.6)Al_(10.8)Ti_(0.6)Ni_(0.6)O₁₉, Ca_(0.2)Sr_(0.8)Al_(10.4)Ti_(0.8)Ni_(0.8)O₁₉, SrAl₁₀TiNiO₁₉, SrAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉, SrAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, SrAl₈Ti₂Ni₂O₁₉, Ca_(0.5)Sr_(0.5)Al₈Ti₂Ni₂O₁₉, Ca_(0.5)Sr_(0.5)Al₁₀TiNiO₁₉, Ca_(0.5)Sr_(0.5)Al₁₀GeNiO₁₉, Ca_(0.5)Sr_(0.5)Al₁₁Sn_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)Sr_(0.5)Al₁₀SnNiO₁₉, Sr_(0.9)La_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Sr_(0.8)La_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.7)La_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Sr_(0.6)La_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Sr_(0.5)La_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Sr_(0.4)La_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Sr_(0.3)La_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Sr_(0.2)La_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Sr_(0.1)La_(0.9)Al_(11.1)Ni_(0.9)O₁₉, Ca_(0.9)La_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)La_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)La_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)La_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)La_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)La_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)La_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)La_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)La_(0.9)Al_(11.1)Ni_(0.9)O₁₉, LaAl₁₁NiO₁₉, Ca_(0.75)La_(0.25)Al_(11.25)Ti_(0.25)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)La_(0.5)Al_(10.5)Ti_(0.5)NiO₁₉, Ca_(0.25)La_(0.75)Al_(9.75)Ti_(0.75)Ni_(1.5)O₁₉, Ca_(0.5)La_(0.5)Al_(8.5)Ti_(1.5)Ni₂ 0 ₁₉, LaAl₉TiNi₂O₁₉, Ca_(0.5)La_(0.5)Al₁₁In_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Ga_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Ge_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Sn_(0.25)Ni_(0.75)O₁₉, Ca_(0.75)La_(0.25)Al_(11.75)Ni_(0.25)O₁₉, Ca_(0.5)Y_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)Ce_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)Pr_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)Na_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.5)K_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.5)Rb_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.5)Cs_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.8)Mg_(0.2)Al_(11.6)Ti_(0.2)Ni_(0.2)O₁₉, Ca_(0.5)Ba_(0.5)Al₈Ti₂Ni₂O₁₉, Sr_(0.9)Y_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Sr_(0.8)Y_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.8)Ce_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.8)Nd_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.8)Pr_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.9)Y_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Y_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Y_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Y_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)La_(0.5)Al_(10.5)Zn_(0.5)Sn_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al_(10.5)Cu_(0.5)Sn_(0.5)Ni_(0.5)O₁₉, Ca_(0.8)Sc_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.8)Yb_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Sr_(0.3)Al_(11.5)Ni_(0.5)O₁₉, CaAl₇Ti_(1.5)Ge_(0.5)MgNi₂O₁₉, Ca_(0.9)Ce_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Ce_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Ce_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Ce_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)Ce_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)Ce_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)Ce_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)Ce_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)Ce_(0.9)Al_(11.1)Ni_(0.9)O₁₉, CeAl₁₁NiO₁₉, Ca_(0.9)Pr_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Pr_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Pr_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Pr_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)Pr_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)Pr_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)Pr_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)Pr_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)Pr_(0.9)Al_(11.1)Ni_(0.9)O₁₉, PrAl₁₁NiO₁₉, Ca_(0.9)Nd_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Nd_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Nd_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Nd_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)Nd_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)Nd_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)Nd_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)Nd_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)Nd_(0.9)Al_(11.1)Ni_(0.9)O₁₉, NdAl₁₁NiO₁₉, CaAl_(11.4)Nb_(0.2)Ni_(0.4)O₁₉, CaAl_(11.4)Ta_(0.2)Ni_(0.4)O₁₉, CaAl_(11.4)V_(0.2)Ni_(0.4)O₁₉, CaAl_(11.4)Sb_(0.2)Ni_(0.4)O₁₉, CaAl₁₁Zr_(0.5)Ni_(0.5)O₁₉ or CaAl₁₁Te_(0.5)Ni_(0.5)O₁₉.

In any of the above embodiments the compounds may have a hibonite crystal structure, and in any of the above embodiments the compounds may be chromophoric. In some embodiments, the compounds are blue. In particular embodiments, disclosed compounds have a blue color with a wavelength of from about 440 nm to about 510 nm, preferably from about 450 nm to about 475 nm. In certain working embodiments, compounds where M^(a) comprised Ni had a blue color.

II. Method of Making Compounds

A general method for making the compounds disclosed herein comprises providing a mixture of reactants selected to produce a desired compound and heating the reactants.

The compounds can be made in different forms, such as powders and pellets. To make pellets of the disclosed compounds, the metals desired in the final compounds are selected. Reactants are then combined in stoichiometric amounts to achieve the desired final ratio of the metals in the compound. Reactants suitable to make the disclosed compounds include elemental metals, and compounds that comprise the desired metals, including, but not limited to, oxides, carbonates, nitrates, nitrites, nitrides, azides, sulfates, sulfites, halides such as chloride, bromide, iodide or fluoride, phosphates, hydroxides, hydrates, or any combination thereof. In some embodiments, the reactants are either metal oxides, or compounds that decompose to provide metal oxides. In working embodiments, the alkali metals and alkaline earth metals were typically provided as metal carbonate salts, and the other metals were typically provided as metal oxides. In some embodiments, the reactants are ground to a powder, either before, during or after mixing, and optionally formed into a pellet.

The combination of reactants is then heated at an effective temperature for an effective period of time to form the desired compound. In some embodiments, the temperature is from about 800° C. to about 2,000° C., typically from about 1,100° C. to about 1,700° C., and even more typically from about 1,200° C. to about 1,500° C. The effective period of time is from greater than zero hours up to at least 72 hours, typically from about 4 hours to about 60 hours, and more typically from about 10 hours to about 48 hours. In some embodiments, reactants are heated at an effective temperature in the presence of air. A person of ordinary skill in the art will appreciate that, if atmospheric oxygen is not required to produce desired compounds, reactants can be heated in an inert atmosphere. A person of ordinary skill in the art also will appreciate that a pressure effective to produce the desired compounds could be about atmospheric pressure or less than atmospheric pressure, such as from less than 1 mm Hg to about 760 mmHg, preferably from about 10 mm Hg to about 700 mm Hg. Or the pressure could be greater than atmospheric pressure, such as from about 1 atmosphere pressure to greater than 10 atmospheres, preferably from about 1.1 atmospheres to about 5 atmospheres pressure.

After heating, the compounds are characterized by X-ray diffraction. If the X-ray diffraction indicates that the compound is impure, i.e. it is not a single phase, the compound is ground into a powder, re-pelletized and reheated. The reheating temperature could be substantially the same as the initial heating temperature, or it could be higher or lower than the initial heating temperature. The pellet is typically reheated for from about 2 to about 48 hours. The grinding, re-pelletizing and reheating is repeated until the X-ray diffraction indicates a pure compound, i.e. a single phase. In certain working embodiments, the combination of reactants was heated at about 1,300° C. for about 12 hours, then ground to a powder, re-pelletized and reheated at from about 1,300° C. to about 1,500° C. for about 12 hours. To make powders of the disclosed compound, the pellets are ground after the final heating step.

Exemplary compounds made according to the disclosed method are characterized by X-ray diffraction, diffuse reflectance spectroscopy and magnetic susceptibility. Table 1, below, lists exemplary compounds and information regarding their color, starting materials and reaction conditions.

TABLE 1 Composition, color and structures of exemplary compounds Heating Temperatures Composition Color Starting Materials and Times CaAl₁₂O₁₉ white CaCO₃, Al₂O₃ 1^(st): 1300° C., 12 hr; 2^(nd): 1500° C., 12 hr CaAl_(11.8)Mn_(0.2)O₁₉ tan/burlywood CaCO₃, Al₂O₃, Mn₂O₃ 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.5)Mn_(0.5)O₁₉ gray CaCO₃, Al₂O₃, Mn₂O₃ 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.8)Ni_(0.2)O₁₉ pale turquoise CaCO₃, Al₂O₃, NiO 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.5)Ni_(0.5)O₁₉ light sky blue CaCO₃, Al₂O₃, NiO 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.8)Co_(0.2)O₁₉ light purplish CaCO₃, Al₂O₃, Co₃O₄ 1^(st): 1300° C., 12 hr; blue 2^(nd): 1450° C., 12 hr CaAl_(11.8)Ti_(0.2)O₁₉ white CaCO₃, Al₂O₃, TiO₂ 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.8)Cr_(0.2)O₁₉ light pink CaCO₃, Al₂O₃, Cr₂O₃ 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.8)V_(0.2)O₁₉ mint cream CaCO₃, Al₂O₃, V₂O₅ 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl_(11.8)Cu_(0.2)O₁₉ misty rose CaCO₃, Al₂O₃, CuO 1^(st): 1300° C., 12 hr; 2^(nd): 1450° C., 12 hr CaAl₁₁Sn_(0.5)Mn_(0.5)O₁₉ light pink CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; Mn₂O₃ 2^(nd): 1450° C., 12 hr CaAl₁₁Sn_(0.5)Ni_(0.5)O₁₉ sky blue CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl₁₀SnNiO₁₉ deep sky blue CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr CaAl₁₁Sn_(0.5)Fe_(0.5)O₁₉ light greenish CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; beige Fe₂O₃ 2^(nd): 1450° C., 12 hr CaAl₁₁Sn_(0.5)Cu_(0.5)O₁₉ White CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; CuO 2^(nd): 1450° C., 12 hr CaAl₁₁Sn_(0.5)Cr_(0.5)O₁₉ light pink CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; Cr₂O₃ 2^(nd): 1450° C., 12 hr CaAl₁₁Zn_(0.5)Ni_(0.5)O₁₉ light blue CaCO₃, Al₂O₃, ZnO, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl₁₁Ge_(0.5)Ni_(0.5)O₁₉ sky blue CaCO₃, Al₂O₃, GeO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl₁₀GeNiO₁₉ deep sky blue CaCO₃, Al₂O₃, GeO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr CaAl₁₁Ga_(0.5)Ni_(0.5)O₁₉ light turquoise CaCO₃, Al₂O₃, 1^(st): 1300° C., 12 hr; Ga₂O₃, NiO 2^(nd): 1450° C., 12 hr CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉ deep sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl₁₁Ti_(0.5)Cu_(0.5)O₁₉ ivory CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; CuO 2^(nd): 1450° C., 12 hr CaAl₁₁Ti_(0.5)Fe_(0.5)O₁₉ light dark khaki CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; Fe₂O₃ 2^(nd): 1450° C., 12 hr CaAl₁₁Ti_(0.5)Mn_(0.5)O₁₉ very light pink CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; Mn₂O₃ 2^(nd): 1450° C., 12 hr CaAl₁₀Ti_(0.5)Si_(0.5)NiO₁₉ sky blue CaCO₃, Al₂O₃, 1^(st): 1300° C., 12 hr; TiO₂, SiO₂, NiO 2^(nd): 1450° C., 12 hr CaAl₁₀Ti_(0.5)Ge_(0.5)NiO₁₉ royal blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; GeO₂, NiO 2^(nd): 1450° C., 12 hr CaAl₁₀Ti_(0.5)Sn_(0.5)NiO₁₉ deep sky blue CaCO₃, Al₂O₃, 1^(st): 1300° C., 12 hr; TiO₂, SnO₂, NiO 2^(nd): 1450° C., 12 hr CaAl₈TiSnNi₂O₁₉ dark CaCO₃, Al₂O₃, 1^(st): 1300° C., 12 hr; turquoise/cyan TiO₂, SnO₂, NiO 2^(nd): 1350° C., 12 hr CaAl₁₀TiNi_(0.5)Cu_(0.5)O₁₉ dark slate gray CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; CuO, NiO 2^(nd): 1450° C., 12 hr CaAl₁₀TiNi_(0.5)Cr_(0.5)O₁₉ dark turquoise CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; Cr₂O₃ 2^(nd): 1450° C., 12 hr CaAl₁₀TiNi_(0.5)Zn_(0.5)O₁₉ deep sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; CuO, NiO 2^(nd): 1450° C., 12 hr CaAl_(11.8)Ti_(0.1)Ni_(0.1)O₁₉ light sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl_(11.6)Ti_(0.2)Ni_(0.2)O₁₉ sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl_(11.4)Ti_(0.3)Ni_(0.3)O₁₉ sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl_(11.2)Ti_(0.4)Ni_(0.4)O₁₉ deep sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉ deep sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr CaAl_(10.8)Ti_(0.6)Ni_(0.6)O₁₉ dark sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1350° C., 12 hr CaAl_(10.6)Ti_(0.7)Ni_(0.7)O₁₉ dodger blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1350° C., 12 hr CaAl_(10.4)Ti_(0.8)Ni_(0.8)O₁₉ dodger blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr CaAl_(10.2)Ti_(0.9)Ni_(0.9)O₁₉ dodger blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr CaAl₁₀TiNiO₁₉ deep sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr CaAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉ royal blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr CaAl₈Ti₂Ni₂O₁₉ dark sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr CaAl₁₁Ge_(0.5)Mn_(0.5)O₁₉ light salmon CaCO₃, Al₂O₃, GeO₂, 1^(st): 1300° C., 12 hr; MnO 2^(nd): 1400° C., 12 hr CaAl₁₁In_(0.5)Mn_(0.5)O₁₉ saddle brown CaCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, In₂O₃, Mn₂O₃ 2^(nd): 1400° C., 12 hr CaAl₁₁Sn_(0.5)Mn_(0.5)O₁₉ light pink CaCO₃, Al₂O₃, SnO₂, 1^(st): 1300° C., 12 hr; MnO 2^(nd): 1400° C., 12 hr CaAl₁₁Ti_(0.5)Mn_(0.5)O₁₉ tan CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; MnO 2^(nd): 1400° C., 12 hr Ca_(0.8)Sr_(0.2)Al_(11.6)Ti_(0.2)Ni_(0.2)O₁₉ light sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.6)Sr_(0.4)Al_(11.2)Ti_(0.4)Ni_(0.4)O₁₉ sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.4)Sr_(0.6)Al_(10.8)Ti_(0.6)Ni_(0.6)O₁₉ darker sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.2)Sr_(0.8)Al_(10.4)Ti_(0.6)Ni_(0.8)O₁₉ darker sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr SrAl₁₀TiNiO₁₉ deep sky blue SrCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr SrAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉ deep sky blue SrCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr SrAl₁₁Ti_(0.5)Ni_(0.5)O₁₉ light blue SrCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr SrAl₈Ti₂Ni₂O₁₉ dark SrCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; turquoise/cyan NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)Sr_(0.5)Al₈Ti₂Ni₂O₁₉ dark turquoise CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)Sr_(0.5)Al₁₀TiNiO₁₉ dodger blue CaCO, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)Sr_(0.5)Al₁₀GeNiO₁₉ deep sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, GeO₂, NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)Sr_(0.5)Al₁₁Sn_(0.5)Ni_(0.5)O₁₉ sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; (bright) Al₂O₃, SnO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)Sr_(0.5)Al₁₀SnNiO₁₉ deep sky blue CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, SnO₂, NiO 2^(nd): 1300° C., 12 hr Sr_(0.9)La_(0.1)Al_(11.9)Ni_(0.1)O₁₉ Light Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.8)La_(0.2)Al_(11.8)Ni_(0.2)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.7)La_(0.3)Al_(11.7)Ni_(0.3)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.6)La_(0.4)Al_(11.6)Ni_(0.4)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.5)La_(0.5)Al_(11.5)Ni_(0.5)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr Sr_(0.4)La_(0.6)Al_(11.4)Ni_(0.6)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr Sr_(0.3)La_(0.7)Al_(11.3)Ni_(0.7)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1350° C., 12 hr Sr_(0.2)La_(0.8)Al_(11.2)Ni_(0.8)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1350° C., 12 hr Sr_(0.1)La_(0.9)Al_(11.1)Ni_(0.9)O₁₉ Sky Blue SrCO₃, La₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr SrAl₁₂O₁₉ white SrCO₃, Al₂O₃ 1^(st): 1300° C., 12 hr; 2^(nd): 1500° C., 12 hr Ca_(0.9)La_(0.1)Al_(11.9)Ni_(0.1)O₁₉ Light Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.8)La_(0.2)Al_(11.8)Ni_(0.2)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.7)La_(0.3)Al_(11.7)Ni_(0.3)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.6)La_(0.4)Al_(11.6)Ni_(0.4)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.5)La_(0.5)Al_(11.5)Ni_(0.5)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.4)La_(0.6)Al_(11.4)Ni_(0.6)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.3)La_(0.7)Al_(11.3)Ni_(0.7)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1350° C., 12 hr Ca_(0.2)La_(0.8)Al_(11.2)Ni_(0.8)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1350° C., 12 hr Ca_(0.1)La_(0.9)Al_(11.1)Ni_(0.9)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1300° C., 12 hr LaAl₁₁NiO₁₉ Sky Blue La₂O₃, Al₂O₃, NiO 1^(st): 1300° C., 12 hr; 2^(nd): 1300° C., 12 hr Ca_(0.75)La_(0.25)Al_(11.25)Ti_(0.25)Ni_(0.5)O₁₉ deep sky blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)La_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉ deep sky blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; (brighter) Al₂O₃, TiO₂, NiO 2^(nd): 1350° C., 12 hr Ca_(0.5)La_(0.5)Al_(10.5)Ti_(0.5)NiO₁₉ royal blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; (darker) Al₂O₃, TiO₂, NiO 2^(nd): 1450° C., 12 hr Ca_(0.25)La_(0.75)Al_(9.75)Ti_(0.75)Ni_(1.5)O₁₉ royal blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; (darkest) Al₂O₃, TiO₂, NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)La_(0.5)Al_(8.5)Ti_(1.5)Ni₂O₁₉ dark turquoise CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1300° C., 12 hr LaAl₉TiNi₂O₁₉ dark turquoise La₂O₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)La_(0.5)Al₁₁In_(0.5)Ni_(0.5)O₁₉ light cyan CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, In₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)La_(0.5)Al₁₁Ga_(0.5)Ni_(0.5)O₁₉ light cyan CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, Ga₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)La_(0.5)Al₁₁Ge_(0.25)Ni_(0.75)O₁₉ deep sky blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, GeO₂, NiO 2^(nd): 1350° C., 12 hr Ca_(0.5)La_(0.5)Al₁₁Sn_(0.25)Ni_(0.75)O₁₉ deep sky blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, SnO₂, NiO 2^(nd): 1350° C., 12 hr Ca_(0.75)La_(0.25)Al_(11.75)Ni_(0.25)O₁₉ Sky Blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.5)Y_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉ turquoise CaCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; TiO₂, NiO 2^(nd): 1350° C., 12 hr Ca_(0.5)Ce_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉ deep sky blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; TiO₂, NiO 2^(nd): 1350° C., 12 hr Ca_(0.5)Pr_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉ deep sky blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1350° C., 12 hr Ca_(0.5)Na_(0.5)Al_(10.5)TiNi_(0.5)O₁₉ bright royal CaCO₃, Na₂CO₃, 1^(st): 1300° C., 12 hr; blue Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)K_(0.5)Al_(10.5)TiNi_(0.5)O₁₉ deep sky blue CaCO₃, K₂CO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)Rb_(0.5)Al_(10.5)TiNi_(0.5)O₁₉ royal blue CaCO₃, Rb₂CO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)Cs_(0.5)Al_(10.5)TiNi_(0.5)O₁₉ deep sky blue CaCO₃, Cs₂CO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1400° C., 12 hr Ca_(0.8)Mg_(0.2)Al_(11.6)Ti_(0.2)Ni_(0.2)O₁₉ light sky blue CaCO₃, MgO, Al₂O₃, 1^(st): 1300° C., 12 hr; TiO₂, NiO 2^(nd): 1450° C., 12 hr Ca_(0.5)Ba_(0.5)Al₈Ti₂Ni₂O₁₉ dark turquoise CaCO₃, BaCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, TiO₂, NiO 2^(nd): 1300° C., 12 hr Sr_(0.9)Y_(0.1)Al_(11.9)Ni_(0.1)O₁₉ light sky blue SrCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.8)Y_(0.2)Al_(11.8)Ni_(0.2)O₁₉ sky blue SrCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.8)Ce_(0.2)Al_(11.8)Ni_(0.2)O₁₉ sky blue SrCO₃, CeO₄, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.8)Nd_(0.2)Al_(11.8)Ni_(0.2)O₁₉ sky blue SrCO₃, Nd₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Sr_(0.8)Pr_(0.2)Al_(11.8)Ni_(0.2)O₁₉ sky blue SrCO₃, Pr₆O₁₁, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.9)Y_(0.1)Al_(11.9)Ni_(0.1)O₁₉ Light Sky Blue CaCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.8)Y_(0.2)Al_(11.8)Ni_(0.2)O₁₉ Sky Blue CaCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.7)Y_(0.3)Al_(11.7)Ni_(0.3)O₁₉ Sky Blue CaCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.6)Y_(0.4)Al_(11.6)Ni_(0.4)O₁₉ Sky Blue CaCO₃, Y₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr Ca_(0.5)La_(0.5)Al_(10.5)Zn_(0.5)Sn_(0.5)Ni_(0.5)O₁₉ Dark bluish CaCO_(3,) La₂O₃, 1^(st): 1300° C., 12 hr; turquoise Al₂O₃, ZnO, SnO₂, 2^(nd): 1400° C., 12 hr NiO Ca_(0.5)La_(0.5)Al_(10.5)Cu_(0.5)Sn_(0.5)Ni_(0.5)O₁₉ deep sky blue CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, CuO, SnO₂, 2^(nd): 1400° C., 12 hr NiO Ca_(0.8)Sc_(0.2)Al_(11.8)Ni_(0.2)O₁₉ light blue CaCO₃, Sc₂O₃, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.8)Yb_(0.2)Al_(11.8)Ni_(0.5)O₁₉ light blue CaCO₃, Yb₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.7)Sr_(0.3)Al_(11.5)Ni_(0.5)O₁₉ light turquoise CaCO₃, SrCO₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr CaAl₇Ti_(1.5)Ge_(0.5)MgNi₂O₁₉ sky blue CaCO₃, Al₂O₃, TiO₂, 1^(st): 1300° C., 12 hr; GeO₂, MgO, NiO 2^(nd): 1300° C., 12 hr Ca_(0.5)La_(0.5)Al_(11.5)Mn_(0.5)O₁₉ saddle brown CaCO₃, La₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, MnO 2^(nd): 1400° C., 12 hr Ca_(0.9)Ce_(0.1)Al_(11.9)Ni_(0.1)O₁₉ Light Sky CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; Blue NiO 2^(nd): 1450° C., 12 hr Ca_(0.8)Ce_(0.2)Al_(11.8)Ni_(0.2)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.7)Ce_(0.3)Al_(11.7)Ni_(0.3)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.6)Ce_(0.4)Al_(11.6)Ni_(0.4)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr Ca_(0.5)Ce_(0.5)Al_(11.5)Ni_(0.5)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr Ca_(0.4)Ce_(0.6)Al_(11.4)Ni_(0.6)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1400° C., 12 hr Ca_(0.3)Ce_(0.7)Al_(11.3)Ni_(0.7)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1350° C., 12 hr Ca_(0.2)Ce_(0.8)Al_(11.2)Ni_(0.8)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1350° C., 12 hr Ca_(0.1)Ce_(0.9)Al_(11.1)Ni_(0.9)O₁₉ Sky Blue CaCO₃, CeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1300° C., 12 hr CeAl₁₁NiO₁₉ Sky Blue CeO₂, Al₂O₃, NiO 1^(st): 1300° C., 12 hr; 2^(nd): 1300° C., 12 hr Ca_(0.9)Pr_(0.1)Al_(11.9)Ni_(0.1)O₁₉ Light Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.8)Pr_(0.2)Al_(11.8)Ni_(0.2)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.7)Pr_(0.3)Al_(11.7)Ni_(0.3)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.6)Pr_(0.4)Al_(11.6)Ni_(0.4)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.5)Pr_(0.5)Al_(11.5)Ni_(0.5)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.4)Pr_(0.6)Al_(11.4)Ni_(0.6)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.3)Pr_(0.7)Al_(11.3)Ni_(0.7)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1350° C., 12 hr Ca_(0.2)Pr_(0.8)Al_(11.2)Ni_(0.8)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1350° C., 12 hr Ca_(0.1)Pr_(0.9)Al_(11.1)Ni_(0.9)O₁₉ Sky Blue CaCO₃, Pr₆O₁₁, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1300° C., 12 hr PrAl₁₁NiO₁₉ Sky Blue Pr₆O₁₁, Al₂O₃, NiO 1^(st): 1300° C., 12 hr; 2^(nd): 1300° C., 12 hr Ca_(0.9)Nd_(0.1)Al_(11.9)Ni_(0.1)O₁₉ Light Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.8)Nd_(0.2)Al_(11.8)Ni_(0.2)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.7)Nd_(0.3)Al_(11.7)Ni_(0.3)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.6)Nd_(0.4)Al_(11.6)Ni_(0.4)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr Ca_(0.5)Nd_(0.5)Al_(11.5)Ni_(0.5)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.4)Nd_(0.6)Al_(11.4)Ni_(0.6)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1400° C., 12 hr Ca_(0.3)Nd_(0.7)Al_(11.3)Ni_(0.7)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1350° C., 12 hr Ca_(0.2)Nd_(0.8)Al_(11.2)Ni_(0.8)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1350° C., 12 hr Ca_(0.1)Nd_(0.9)Al_(11.1)Ni_(0.9)O₁₉ Sky Blue CaCO₃, Nd₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1300° C., 12 hr NdAl₁₁NiO₁₉ Sky Blue Nd₂O₃, Al₂O₃, NiO 1^(st): 1300° C., 12 hr; 2^(nd): 1300° C., 12 hr CaAl_(11.4)Nb_(0.2)Ni_(0.4)O₁₉ Deep sky blue CaCO₃, Nb₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr CaAl_(11.4)Ta_(0.2)Ni_(0.4)O₁₉ Deep sky blue CaCO₃, Ta₂O₅, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr CaAl_(11.4)V_(0.2)Ni_(0.4)O₁₉ Turquoise CaCO₃, V₂O₅, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl_(11.4)Sb_(0.2)Ni_(0.4)O₁₉ Sky blue CaCO₃, Sb₂O₃, 1^(st): 1300° C., 12 hr; Al₂O₃, NiO 2^(nd): 1450° C., 12 hr CaAl₁₁Zr_(0.5)Ni_(0.5)O₁₉ Light sky blue CaCO₃, ZrO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; NiO 2^(nd): 1450° C., 12 hr CaAl₁₁Te_(0.5)Ni_(0.5)O₁₉ Very light sky CaCO₃, TeO₂, Al₂O₃, 1^(st): 1300° C., 12 hr; blue NiO 2^(nd): 1450° C., 12 hr

The colors can be varied or selected by changing the relative ratio of metals in the compound, or by changing the composition. FIG. 3 shows the results of varying the relative ratio of metals in an exemplary series of compounds, CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0-1.2). In this series, the compound when x is 0, i.e. no Ti or Ni present, has a white color. The introduction of Ti and Ni (x=0.1) results in a blue compound. As compounds with increasing amounts of Ti and Ni are synthesized, the colors of the compounds change from a light sky blue at x=0.1 (CaAl_(11.8)Ti_(0.1)Ni_(0.1)O₁₉), through a deep sky blue at x=1.0 (CaAl₁₀TiNiO₁₉), to a royal blue color at x=1.2 (CaAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉). Surprisingly, the color of the pellet is substantially maintained when the pellet is ground to a powder, thereby making the compound suitable for use as a pigment (FIG. 3).

FIG. 4 shows the results of varying the composition of the compounds. In the series of compounds having a formula CaAl_(12−x−y)M_(x)Ni_(y)O₁₉ (x, y=0.2-0.5), where M is Ti, Sn, Ge, Sb or Nb, all the samples have a blue color. CaAl₁₁Sn_(0.5)Ni_(0.5)O₁₉ and CaAl_(11.4)Sb_(0.2)Ni_(0.4)O₁₉ have a light sky blue color, and CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, CaAl₁₁Ge_(0.5)Ni_(0.5)O₁₉ and CaAl_(11.4)Nb_(0.2)Ni_(0.4)O₁₉ have a deep sky blue color.

III. Compositions

The present disclosure is also concerns compositions comprising at least one disclosed compound or compounds, particularly a hibonite compound, even more particularly a blue hibonite compound or a compound having formula II, and at least one additional component. Such compositions include a paint, an ink, a dye, a glass, a plastic, an emulsion, a fabric, or a cosmetic preparation. Suitable additional components for use in paint, ink dye or emulsion products include, but are not limited to, binders, solvents, and additives such as catalysts, thickeners, stabilizers, emulsifiers, texturizers, adhesion promoters, UV stabilizers, flatteners (i.e., de-glossing agents), preservatives, and other additives known to those of ordinary skill in the art.

Suitable additional materials for use in glass products include, for example, network formers (e.g., oxides of silicon, boron, germanium) to form a highly crosslinked network of chemical bonds, modifiers (e.g., calcium, lead, lithium, sodium, potassium) that alter the network structure, intermediates (e.g., titanium, aluminum, zirconium, beryllium, magnesium, zinc) that can act as both network formers and modifiers, and combinations thereof.

Suitable additional materials for use in plastic products include, for example, dispersion aids (e.g., zinc stearate, calcium stearate, ethylene bis-steamide), plasticizers, flame retardants, internal mold release agents, slip agents, and combinations thereof.

When coloring a ceramic product, the material typically is added to a ceramic glaze composition. Other materials used in glazes include, for example, silica, metal oxides (e.g., sodium, potassium, calcium), alumina, opacifiers (e.g., tin oxide, zirconium oxide), and combinations thereof.

IV. Working Examples

The compounds disclosed herein were prepared via traditional solid state reactions.

Amounts of metal carbonates and/or metal oxides were selected and weighed to provide the desired stoichiometric amounts of the metals. Typically, the alkali metals and alkaline earth metals were provided as metal carbonate salts, and the other metals were provided as metal oxides. The starting materials were then mixed, ground and pelletized, then heated in air at a range of from about 1,200° C. to about 1,500° C. several times with intermediate grinding. Ramp rates were about 300° C./hour. Table 1, above, gives the starting metal salts and oxides for each exemplary compound, and the heating temperatures and times for each heating cycle. For example, CaCO₃ (0.0721 grams, 1 molar equivalent), Al₂O₃ (0.4039 grams, 5.5 molar equivalents), TiO₂ (0.0288 grams, 0.5 molar equivalents) and NiO (0.0269 grams, 0.5 molar equivalents) were weighed, mixed/ground, pelletized and heated in air at 1,300° C. for 12 hours, then ground to a powder, re-pelletized and reheated at 1,400° C. for 12 hours to prepare 0.5g of CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉.

X-ray diffraction patterns of exemplary solid solutions of CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0.1-1.2) are shown in FIG. 5. The X-ray diffraction data was obtained using a Rigaku Miniflex X-ray diffractometer using Cu Kα radiation and a graphite monochromator. The lattice parameters of the unit cells were calculated by whole pattern fitting as shown in FIG. 6, using the data of CaAl₁₁Sn_(0.5)Ni_(0.5)O₁₉ as an example. The results indicate that cell edge ‘a’ was 5.6075 Å, ‘c’ was 22.205 Å and the cell volume was 604.69 Å³. In comparison, for CaAl₁₂O₁₉ cell edge ‘a’ was 5.5636 Å, ‘c’ was 21.945 Å and the cell volume was 588.28 Å³. The increase of hibonite unit cell volume was consistent with the substitution of small Al³⁺ ions with larger Ni²⁺, Ti⁴⁺ and La³⁺ ions (FIGS. 7 and 8).

Diffuse reflectance spectra of powdered samples were obtained in the region 300-1100nm using a Xe lamp and a grating double monochromator as the source. The diffuse light reflected by the powders was collected with an integration sphere and detected with a Si diode detector. MgO was used as a reference. The data were transformed into absorbance using the Kubelka-Munk function.

The 400-800 nm region of diffuse reflectance spectra for solid solution of exemplary compounds CaAl_(12−2x)Ti_(x)Ni_(x)O₁₉ (x=0-1.2) are shown in FIG. 9. Strong absorption in the orange spectral region combined with relatively weak absorption in the blue region was responsible for the observed bright blue color. In pure CaAl₁₂O₁₉ (i.e. x=0), nearly no absorption occurs throughout the entire visible region, resulting in the white color. With increasing Ni composition, the onset of the first absorption peak shifts to lower energy and the second broadens, consistent with the gradual darkening of the samples toward royal blue.

In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims. 

We claim:
 1. A compound having a formula AAl_(12−x−y)M^(a) _(x)M^(b) _(y)O₁₉, wherein: A is selected from Ca, Sr, Ba, Mg, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof; M^(a) is selected from Ni, Fe, Cu, Cr, V, Mn, or Co or any combination thereof; M^(b) is selected from Ti, Sn, Ge, Si, Zr, Hf, Ga, In, Zn, Mg, Nb, Ta, Sb, Mo, W or Te or any combination thereof; x is from 0.01 to less than 12; y is from 0 to less than 12; x+y is less than 12; and if y is 0, then x is from 0.01 to less than 1; if M^(a) comprises Fe, then y is greater than 0, or M^(a) further comprises Ni, Cu, Cr, V, Mn, or Co or any combination thereof; and if M^(a) is Mn and M^(b) is Mg, then x+y is less than 1, or x+y is greater than
 1. 2. The compound of claim 1, wherein x is from 0.01 to less than 12 and y is from 0.01 to less than
 12. 3. The compound of claim 1, wherein: A is A¹ _(1−z)A² _(z); A¹ is selected from Ca, Sr, Ba, Mg, Sc, Y, Li, Na, K, Rb, Cs, Pb, Bi or any combination thereof; A² is selected from La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or any combination thereof; and z is from 0 to less than
 1. 4. The compound of claim 1, wherein the compound is selected from CaAl_(11.8)Ni_(0.2)O₁₉, CaAl_(11.5)Ni_(0.5)O₁₉, CaAl₁₁Sn_(0.5)Ni_(0.5)O₁₉, CaAl₁₀SnNiO₁₉, CaAl₁₁Zn_(0.5)Ni_(0.5)O₁₉, CaAl₁₁Ge_(0.5)Ni_(0.5)O₁₉, CaAl₁₀GeNiO₁₉, CaAl₁₁Ga_(0.5)Ni_(0.5)O₁₉, CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, CaAl₁₀Ti_(0.5)Si_(0.5)NiO₁₉, CaAl₁₀Ti_(0.5)Ge_(0.5)NiO₁₉, CaAl₁₀Ti_(0.5)Sn_(0.5)NiO₁₉, CaAl₈TiSnNi₂O₁₉, CaAl₁₀TiNi_(0.5)Cu_(0.5)O₁₉, CaAl₁₀TiNi_(0.5)Cr_(0.5)O₁₉, CaAl₁₀TiNi_(0.5)Zn_(0.5)O₁₉, CaAl_(11.8)Ti_(0.1)Ni_(0.1)O₁₉, CaAl_(11.6)Ti_(0.2)Ni_(0.2)O₁₉, CaAl_(11.4)Ti_(0.3)Ni_(0.3)O₁₉, CaAl_(11.2)Ti_(0.4)Ni_(0.4)O₁₉, CaAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, CaAl_(10.8)Ti_(0.6)Ni_(0.6)O₁₉, CaAl_(10.6)Ti_(0.7)Ni_(0.7)O₁₉, CaAl_(10.4)Ti_(0.8)Ni_(0.8)O₁₉, CaAl_(10.2)Ti_(0.9)Ni_(0.9)O₁₉, CaAl₁₀TiNiO₁₉, CaAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉, CaAl₈Ti₂Ni₂O₁₉, Ca_(0.8)Sr_(0.2)Al_(11.6)Ti_(0.2)Ni_(0.2)O₁₉, Ca_(0.6)Sr_(0.4)Al_(11.2)Ti_(0.4)Ni_(0.4)O₁₉, Ca_(0.4)Sr_(0.6)Al_(10.8)Ti_(0.6)Ni_(0.6)O₁₉, Ca_(0.2)Sr_(0.8)Al_(10.4)Ti_(0.8)Ni_(0.8)O₁₉, SrAl₁₀TiNiO₁₉, SrAl_(9.6)Ti_(1.2)Ni_(1.2)O₁₉, SrAl₁₁Ti_(0.5)Ni_(0.5)O₁₉, SrAl₈Ti₂Ni₂O₁₉, Ca_(0.5)Sr_(0.5)Al₈Ti₂Ni₂O₁₉, Ca_(0.5)Sr_(0.5)Al₁₀TiNiO₁₉, Ca_(0.5)Sr_(0.5)Al₁₀GeNiO₁₉, Ca_(0.5)Sr_(0.5)Al₁₁Sn_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)Sr_(0.5)Al₁₀SnNiO₁₉, Sr_(0.9)La_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Sr_(0.8)La_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.7)La_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Sr_(0.6)La_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Sr_(0.5)La_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Sr_(0.4)La_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Sr_(0.3)La_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Sr_(0.2)La_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Sr_(0.1)La_(0.9)Al_(11.1)Ni_(0.9)O₁₉, Ca_(0.9)La_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)La_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)La_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)La_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)La_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)La_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)La_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)La_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)La_(0.9)Al_(11.1)Ni_(0.9)O₁₉, Ca_(0.75)La_(0.25)Al_(11.25)Ti_(0.25)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)La_(0.5)Al_(10.5)Ti_(0.5)NiO₁₉, Ca_(0.25)La_(0.75)Al_(9.75)Ti_(0.75)Ni_(1.5)O₁₉, Ca_(0.5)La_(0.5)Al_(8.5)Ti_(1.5)Ni₂O₁₉, LaAl₉TiNi₂O₁₉, Ca_(0.5)La_(0.5)Al₁₁In_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Ga_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Ge_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)La_(0.5)Al₁₁Sn_(0.25)Ni_(0.75)O₁₉, Ca_(0.75)La_(0.25)Al_(11.75)Ni_(0.25)O₁₉, Ca_(0.5)Y_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)Ce_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)Pr_(0.5)Al₁₁Ti_(0.25)Ni_(0.75)O₁₉, Ca_(0.5)Na_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.5)K_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.5)Rb_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.5)Cs_(0.5)Al_(10.5)TiNi_(0.5)O₁₉, Ca_(0.8)Mg_(0.2)Al_(11.6)Ti_(0.2)Ni_(0.2)O₁₉, Ca_(0.5)Ba_(0.5)Al₈Ti₂Ni₂O₁₉, Sr_(0.9)Y_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Sr_(0.8)Y_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.8)Ce_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.8)Nd_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Sr_(0.8)Pr_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.9)Y_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Y_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Y_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Y_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)La_(0.5)Al_(10.5)Zn_(0.5)Sn_(0.5)Ni_(0.5)O₁₉, Ca_(0.5)La_(0.5)Al_(10.5)Cu_(0.5)Sn_(0.5)Ni_(0.5)O₁₉, Ca_(0.8)Sc_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.8)Yb_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Sr_(0.3)Al_(11.5)Ni_(0.5)O₁₉, CaAl₇Ti_(1.5)Ge_(0.5)MgNi₂O₁₉, Ca_(0.9)Ce_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Ce_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Ce_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Ce_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)Ce_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)Ce_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)Ce_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)Ce_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)Ce_(0.9)Al_(11.1)Ni_(0.9)O₁₉, Ca_(0.9)Pr_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Pr_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Pr_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Pr_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)Pr_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)Pr_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)Pr_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)Pr_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)Pr_(0.9)Al_(11.1)Ni_(0.9)O₁₉, Ca_(0.9)Nd_(0.1)Al_(11.9)Ni_(0.1)O₁₉, Ca_(0.8)Nd_(0.2)Al_(11.8)Ni_(0.2)O₁₉, Ca_(0.7)Nd_(0.3)Al_(11.7)Ni_(0.3)O₁₉, Ca_(0.6)Nd_(0.4)Al_(11.6)Ni_(0.4)O₁₉, Ca_(0.5)Nd_(0.5)Al_(11.5)Ni_(0.5)O₁₉, Ca_(0.4)Nd_(0.6)Al_(11.4)Ni_(0.6)O₁₉, Ca_(0.3)Nd_(0.7)Al_(11.3)Ni_(0.7)O₁₉, Ca_(0.2)Nd_(0.8)Al_(11.2)Ni_(0.8)O₁₉, Ca_(0.1)Nd_(0.9)Al_(11.1)Ni_(0.9)O₁₉, CaAl_(11.4)Nb_(0.2)Ni_(0.4)O₁₉, CaAl_(11.4)Ta_(0.2)Ni_(0.4)O₁₉, CaAl_(11.4)V_(0.2)Ni_(0.4)O₁₉, CaAl_(11.4)Sb_(0.2)Ni_(0.4)O₁₉, CaAl₁₁Zr_(0.5)Ni_(0.5)O₁₉ or CaAl₁₁Te_(0.5)Ni_(0.5)O₁₉.
 5. The compound of claim 1, wherein M^(a) comprises Ni, Co or any combination thereof.
 6. The compound of claim 1 wherein M^(a) is Ni.
 7. The compound of claim 1, wherein x+y is less than or equal to
 4. 8. The compound of claim 1, wherein y is from 0 to
 2. 9. The compound of claim 8, wherein x is from 0.01 to
 2. 10. The compound of claim 1, wherein the compound has a blue color.
 11. The compound of claim 10, wherein the blue color has a wavelength of from about 440 nm to about 510 nm.
 12. The compound of claim 10, wherein the compound has a hibonite crystal structure.
 13. The compound of claim 10, wherein M^(b) comprises Ti.
 14. The compound of claim 10, wherein A comprises Ca, La, Sr or any combination thereof.
 15. The compound of claim 10, wherein M^(a) is Co and x is from 0.05 to 1.5.
 16. The compound of claim 10, wherein: M^(a) is Ni; M^(b) is selected from Ti, Ge, Sn or any combination thereof; and x is from 0.05 to 1.5.
 17. The compound of claim 1, wherein M^(a) comprises at least two metals selected from Ni, Cr, Cu, V, Mn, Co or Fe.
 18. The compound of claim 1, wherein M^(a) comprises V and at least one additional metal selected from Ni, Cr, Cu, Mn, Co or Fe.
 19. The compound of claim 1, wherein M^(a) comprises Cr and at least one additional metal selected from Ni, V, Cu, Mn, Co or Fe.
 20. A composition, comprising: a compound of claim 1; and at least one additional component.
 21. The composition of claim 20, wherein the composition is a paint, an ink, a dye, a glass, a plastic, an emulsion, a fabric, or a cosmetic preparation.
 22. The composition of claim 20, wherein the at least one additional component is a binder, a solvent, a catalyst, a thickener, a stabilizer, an emulsifier, a texturizer, an adhesion promoter, a UV stabilizer, a flattener, a preservative, a polymer, a dispersion aid, a plasticizer, a flame retardant, an oxide of a metal, or any combination thereof.
 23. The composition of claim 20, wherein the composition is a glass, and the at least one additional component is a metal oxide.
 24. The composition of claim 20, further comprising at least one additional compound according to claim
 1. 25. A method for making a compound of claim 1, the method comprising: selecting metals desired in the compound; providing reactants comprising the selected metals; combining the reactants in stoichiometric amounts to achieve a desired final ratio of the selected metals in the compound; and heating the combination of reactants at an effective temperature for an effective period of time to make the compound of claim
 1. 